Directive antenna



Aug. 14, 1928. l,68(,363-

. R. vBowN DIRECTIVE ANTENNA Filed Nov. 13, 1924 3 Sheets-Sheet 1.41ztel'/arzwk I l .2 3 TH* i als Mmm/zia Vltaye Lingue/fum 3 5 Bv yATTORNEY Aug'. 14, 1928.

1,680,363 R. BowN DIRECTIVE` ANTENNA Filed N0v.15, 1924 s sheets-snm 2IN VEN TOR /VTORNE Y Aug. 14, 1928. 1,680,363

R. BOWN DIRECTIVE ANTENNA Filed Nov. 13, 1924 3 Sheets-Sheet 5 Y'Patented Aug. 14, 1.928.

VRALPH BowN, or MAPLEWooD, NEW JERSEY, Assi'GNoB tro AMERICANvTELEPIniNE c lAND TELNGNAPH COMPANY, A conroRArIoN oF@ vNaw YORK;

nranofrrvn ANTENNA.

appliepationnied November 13, ieee. seriar'im.V 749,799.. y

This inventionrelates `to directive radio signaling systems, andparticularly to means for' altering the phase relations between avplurality of alternating currents setup ltheantennae of such systems. vY

In a directive radio signaling system'such asis described inthecopending lapplication 4of Campbell` Serial No. 327,553,ffiledSeptember 30, 1919, a plurality of antennae-are spaced Yapart at equaldistances Yrepresenting a lcommon fraction or'a multiple-"of a wavelength, and each of the antennae is connected V,with acommonrecelvingfcircuit uponnwhich is-impressedV the potentialsset" upinthe antennae of 'suchjsysterm `One `of Lthe objections to an" antennaarray such as disclosed inY the' Campbell application arises from itsspace requirements when intended for use with longwave Vle'n,:0fth`ssuch as are used in transoceanic radiojoperation.l 'For example, ifarectilinear array-of sixteen antennae spaced one-half Xapart is used forthe reception of waveswhose length is 16000 meters, the spacing betweenadjacent an-V tenna is over four miles, and the total length of such anvarray, would be in the neighborhood of sixty miles. From this'it'wilLfo-f course, be'apparent that the spacerequire- One of the objectsof thisrv invention isfto provide a ymethod `and means4 renderingitpracticablejto carry out the, principleY set forth in thefCampbellapplication by an antenna array in -which the distance between f theadjacent antennae is but Ya Qfractionof shown spaced apart byV aldistance equal tol that set forth in the Campbell application. 'Y Other'objects of this inventionv lwill" be apparentl` from .the followingdescription y -when 'read in'connection with theV attached drawing'ofwhich Figures 1, 2 and'` 3 show Y graphically 'the principles uponfwhich' my yi'nventionrest; Fig. 4 shows aV form of the circuit inwhichitis-embodied; and Fig. 5y

shows a variation involving intermediate ,1 frequency detection of thevreceived ywaves.

In Fig-1, three antennae of an array are ranged inV anyforin.. -As isvWell known, in

such an. array ,the distancesjbetween 'adj a.- cent;. antennae lisacommon fraction :or .a multiple of the wavelength .;-Assu 1n'e Y that,thisV distance'` ism/u The currents set upl-in thevarious `antennae.due tothe sig'- n'ailng'r waves lhave a 'phase 'difference deter-*mined'fby Athe .-Value of vWand the" angle v'of approach of the wa-Ve.Assuming that the ware approaches the. antenna array -inthedirectionfrepresented by the arrow of` Fig.

-1', ft`he voltageset 'up -in antenna 1 may be vrepresented by curve A,that setup in antenna@ by B, and that inantenna 3 by C.: The phase`relations at any .instant'm'aybe ydetermined from the 1 curves. Aniarra hzwing` al spacing 'equal .to one-half of the ,received wavelengthso that thecurrents set Vnp the respective antennae are one-half aperiod apart; in phase 'has good bilateral reception'quality.As'mentioned heretofore,

zthefspaci-ng-.of the antenna one-half-a wave 'lfen jth` apartrenderssuch a lstructure almost prohibitive. Ilhaveafound that if thelarray -is reduced in 'size to'. the point where. the

`spacing distance is -l/nth fof. its original value, thatii's, where thespacing distance ments of such Va system impose-a great hand- 2 .n @t'henthharmomc's. gf the'elld cap upon itS use', f I voltages willduplicatefthe'V phase relations' existing `between the fundamental.voltages received Vby 'thelmore `widely spaced antenna. :Thisis'cle'arly shownl'in Fig.v2 in which fthe antennae designated :1,2 land3 are show nV ."'spacedapartgbyf 1/6 of `-/\'.`V VVi'th waves of.ith'esame-length as shown'in' Fig. 1 impressed i up'on tlieantennae VofFig.2, the voltagesv in :therespective antennae will" be 1/; of a wave'y r' length "apart ingphase, `but the voltages're'presenting' thel'third harmonic of the received as the fun amentaln frequency shownf inVfrequency will have'thesarn'e phasel relation 'y l I Y vMy' inventiontherefore consists" broadly `in shortening the spacing 'betweentheadjacent antennae of a system by an amountequal to.

A and vthen kproducing harmonics of the'` n 'frequencyset up in eachantennaand selecty ing `"therefrom the nth harmonic for combination'finthe eominonireceiving circuit in losl ' shown'spacedapart a distanceequal to Each antenna is 'connected with a harmonic quen'cy. :If'thenthharmonicisl thethird,y

vproducerby means ofthe circuits 4,' 5 andl 6 which are of equalelectrical len h. `ThisA equalityis maintained'by'-mean`s'o 4theartificial lines,13,14 and 15, and of amplifiersvr rents would beproduced by the devices 7, 8

16, 17 Vand18insertedintlie connecting'lines f4, and (i betweentheantennae and the harmonic" producers. Each of ythe harmonic`producers V7, 8 and 9 is connected-withV the common receivingcircuitwhichlhas therein as part of the'equipmentaba-ndv filter orvother frequency selectivedevicef Yfor Vselecting thenth harmonic of the'Y received fre.-

the antennae .wouldl be spaced'"appart a V distance equal to 1/6' of thereceived' wavelength,

and the third harmonic ofthe receivedlwav'es I would'vbe impressedfupon`the demodulating apparatus :11 the jout ut of 'whichwould be detected-bymeans o the 'signal indicating device 12. ItV willaccordingly be' vseenfrom Fig. 2. thatby spacing the antenna apart a distance equal to 1A;)tand by using the lthird harmonicjof the voltages setv up in Aeach ofthe antennaethe: system will have the "jsame V`directionalcharacteristic as 'an arrayin whichthe antennae arefspaced apart Thearrangement shown in, Fig. 5 islaV modification of the `circuithereinbefore Yd escribed, the modificationconsisting in beat-l ing therrecejivled 1 r'requencyjV to a lower fref`V 'quency beforetransmittingv it v.over the conr necting circuits tothe commonfvcircuitkin which the' Vcurrents from all of the connecting circuits arecombined., .-The vsamenuV meralsv indicate. similar partsjin Figs. LLand5.

ingy circuits4,r5 and A.6 contain not onll Y the apparatus shown in'vFi'gflj. but l' also intermediate frequency detectorsf19, 2O land 21'.

VAfjsourcerof beati'n frequency 22,'whichl v Vpreferably is locateinthev` vicinity of the are vspaced apartjatthe distance varmonicproducers' 7, V8t'and'9 is arranged' gto Ysupply theffrequencynecessary to.beat the frequency .received by the antennae A.1", r 2Y`and 3 to a lowerrfrequency. Afswitch 24-`is t. Y' `In`the operation ofthe systenishown Figi 5- the f received waves Whose lengthV is Y )twillbe impressed upon the antenn which rentof the frequency correspondingt'o will beset up lintheueonnecting circuits 4,5 and' f6 togetherwithcurrent of the beatinglfref j quencyfrom'the ,source 22. The two ifre'-quencies will beat together'in` the detectors A19, and 21, andcurrentsvof an `intermedi-V.

kthei'sam'e characteri'stic.VV .v ,Y While-thisinventionhas.been1described as .appliedtoa directive radio signaling sys,-

Vatefrequency willbe impressed upon the i harmonic producers 7, Sand 9.These currents Ywilhof course, be equalizedv byl the` 1 monicsk 'of theintermediate frequency V'curand 9, and the nth harmonic: wouldbe'passved Aby the'iilter 10v tovthe demodulating appa-' ratus 11.` Thesignal producedfby the de.

,modulating apparatus )would :befindic'a'ted: l'

byi'the device .'12.

It will accordingly beffseen-vthat the phases fof :receivedvoltages setup inthe received. Waves Vwould `not i directly i produce tern, it is:tof be understoodthatit is notfso 1,'In aSystem for changingphaseferences j by lfrequency conversion the cornblnation withan-ante'nna array Yfor: receiv- Vfm limited but is -capable ofapplication' .inrother ways And itis Llikewise .capable of embodilmentinY other forms without Adepartingfrorn 1 Y thespirit and scropefoftheappendedclaimrs- -to and connected With'thesaid antennaeall fl"connectingA circuits;V and `a commen 'trans`- .of said circuits'bei'ngof. the jsamelength`A electrically, an y harmonicl producer Yindividualtoy and connected with each of said lat-ing circuit connectedwith..-the/said.con-'ft f necting v circuits fand v,having Va (frequencyselecting device to transmit '-g-therethro ughl Y l gonly a.predetermined harmonic oifthosejpro'- vduced in eachV of said*Aconnectingycircuits.

2. 'In aA systeinA Afor changing' pbasewdif-Y if ladj acentY antennaebeing equal to "M, -of

Vferences by frequency conversiointhefcomf l. bination'with'anantennafarray forreceiv- Ii-ngi waves of length 5), thedistancebetween and Vconnected Vwith the said -.antenn, each"`connecting.",circuit i having jadj usting` means to vrender theelectrical length thereof equal to that of the other circuits, vaharmonic pro'- j l* i ,ducer individual to and connected with each yofthe said .connecting circuits, andl 'a` -flequency Vselecting devicecommon to"'-all of through rka vpredetermined vharmonic o I' 'those nproduced ina-each ofthe said'connectingcirlff cuits.

.3. InI arsystemlfor changing phaseV diferencesV by. frequencyconversion, theE comsaid connecting circuits toAtransmit-.there- 1.25

so i of my vinvention itjispractic'able tocontrol l lul i rality lofjVconnecting Vcircuits individual to bination with an antenna array forreceiving Waves of length'a, the distance between adjacent antenn beingequal to m, of a plurality of connecting circuits individual to andconnected With the said antenn, each connecting circuitv having anartificial line vand an amplifier to render the electrical lengththereof equal to that vof the other circuits, a harmonic producerindividual to and'coiinected With each of the said connecting circuits,and a frequency selecting device commento all ofsaid connecting circuitsto transmit therethrough' a vpredetermined harmonic of those produced ineach of the said connecting circuits. f

4. Ina system forV changing phaseV diff` ferences by frequencyconversion, the coinrbination With an antenna array for receiving Wavesof length a, the distance between adjacent antennae being equal to m, ofa source 'off beating oscillations Whose frequency, differs from that ofthe received Waves, a plurality of connecting circuits of the sameelectrical length vindividual to each of said antennae, and valsoconnected with said source of oscillations, each connecting Vcircuithaving means to vbeat'the received Waves with thejbeatingloscillationsto produce an intermediate frequency, and' a liarnionicproducer'likeivise individual to each connecting circuit to createharmonics of the frequency produced by the said beating operation, and aLcommon translating circuit having a frequency selecting device Ytotransmit therethrough a predetermined har-k bination with Va pluralityof circuits lof equalv quency applied thereto, and a translatingV` minedharmonic of those produced in the said first mentioned circuits.

6. ln a system for changing phase differences by frequency conversion,the combination with a plurality'of circuits of equal electrical length,of' voltage producing iicans for impressing upon each of the saidcircuits voltages vof the same frequency but differing in phase, thephase difference hetween successively adjacent circuits `being circuitcommon tol all of said first mentioned circuits having means to select apredeter-f) the same, a source of beating oscillations also connectedWith each-of said circuits, the

frequency of said oscillations differing 'from that or the voltageproducing means, each of said'circui-ts having'- means to beat togetherthe said beating' frequency and the vfre- "quency of the voltageimpressed thereon byl the voltage producingmeans to createrranintermediate frequency, means connected with` each of said circuits topro`du`ceharnioni'cs of vthe said intermediate frequency,;,

`and means to select a predetermined vhar-` iiionic of those created bythe rsaid harmonic producing lmeans and a translatingcircuit `uponlWhich the selected harmonic is- 1mpressed. e

In testimony whereof, l have signed my naine to this specification this11th day of'- November, 192

f kRALPH BOWN. i

